Finding the Fourth Proportional to 111.72, 153.70 and 105.96

Step by Step Solution

1. Step 1: Write the proportion equation
   111.72 : 153.70 = 105.96 : x
2. Step 2: Convert to fraction form
   111.72/153.70 = 105.96/x
3. Step 3: Cross multiply
   111.72x = 153.70 × 105.96
4. Step 4: Simplify right side
   111.72x = 16,286.05
5. Step 5: Solve for x
   x = 16,286.05/111.72
6. Step 6: Final answer
   x = 145.78